Abstract
Purpose:
To attest the eligibility of patients with ocular infantile nystagmus syndrome (INS) for photorefractive keratectomy (PRK) and to report the visual and refractive outcomes.
Methods:
This case series comprised 11 individual cases of INS (aged 20 to 46 years; mean 31.45) Nine patients had congenital efferent nystagmus and 2 patients had congenital afferent nystagmus. Six patients referred previous surgery on extraocular muscles in order to reduce nystagmic jerks in primary position (Anderson operation). Objective refraction was evaluated by means of retinoscopy in cycloplegia before and after PRK. All the patients had a compound or mixed astigmatism (from 0.75 to 6 diopters; mean 4.55 - spherical equivalent from +0.25 to -11.25 diopters, mean -3.43). All patients used glasses and two of them used also rigid contact lenses, before refractive surgery. PRK was performed in both eyes (22 eyes) of all the 11 patients. PRK was performed under topic anesthesia using a flying spot and tracking excimer laser. After surgery, patient satisfaction was tested by administering a questionnaire consisting of three multiple-choice questions (score from 0 to 2 for each question).
Results:
Binocular post-operative uncorrected visual acuity compared with pre-operative binocular best corrected visual acuity improved by 2.5 lines on average in group 1 and by 1.25 lines on average in group 2. No patient needed to wear a refractive correction after surgery. Patient’s satisfaction after surgery was great in all patients (mean score 4.5).
Conclusions:
Glasses may be inadequate to improve vision in patients with INS who adopt a compensatory anomalous head posture, because the centre of the pupils coincides with the frame of the spectacles rather than with the centre of the lens, a problem that is even more accentuated when astigmatism is present. Contact lenses may potentially be useful because they move synchronously with the eyes. Nystagmic patients, however, have difficulties both inserting and wearing them. It would appear that refractive surgery represents to date one of the few viable treatment options. Our study shows that patients with INS are eligible for PRK to correct their refractive errors. The results, obtained in the most significant group of treated patients, are excellent, especially considering that it comes to patients in which a difference of one or two optotype lines may be very relevant.
Keywords: 619 nystagmus •
678 refractive surgery •
428 astigmatism